The chance of weather stopping the launch of Space Shuttle Discovery at 20:47h local time (01:47h GMT on Sunday 10 December) has dropped to 30% with only 15kt (17.2km/h) crosswinds at Kennedy Space Center (KSC) threatening the start of mission STS-116.
The crew is aboard and the Orbiter's computers have been loaded with the programmes for the flight. Monitoring the weather at the Shuttle's abort landing sites in the US and Europe the US Air Force 45th weather squadron has a green status for the Trans-Atlantic Abort Landing (TAL) site in France and one of the two in Spain.
Spanish TAL site Zaragoza has a red status and the two US abort sites at White Sands Missile Range in New Mexico and Edwards Air Force Base in California have issues regarding their cloud ceiling, which affects runway visibility for the Shuttle crew, but both locations are still green.
The countdown has stopped at T-9min and will restart at about 20:35h, with the launch window opening for 10min at 20:42h 34s.
Earlier today NASA had to make a decision whether to start fuelling Discovery's external tank (ET) by 13:00h or abandon today's attempt after delays in the 48h turn around required after launch scrub on Thursday 7 December. As it takes around 3h to fuel the ET and because of the many elements required to occur before, during and after that operation to ready a Shuttle to launch, if fuelling had not begun by 13:00h the KSC team would have been unable to have the vehicle prepared for lift off by its launch window.
Weather conditions over KSC on Friday led NASA to opt for Saturday 9 December just an hour after scrubbing that launch of Discovery on Thursday 7 December. Saturday was predicted to have a 70% chance of weather prohibiting launch but during the afternoon and evening that has fallen to 30%. If NASA cannot launch Discovery today the agency will examine its cryogenic propellant resources to determine if Sunday 10 December is the next day for an attempt.
Discovery's mission STS-116 is the 117th Shuttle mission, the 20th US construction mission to the International Space Station (ISS) and the Orbiter's 33rd flight. During the mission's three extra-vehicular activities astronauts will install the P5 port truss segment, retract the P6 port solar array's wing and radiators and move power cables to enable the ISS to draw power from the arrays installed in September by Space Shuttle Atlantis' crew on STS-115.
The STS-116 crew are NASA astronauts William Oefelein, pilot; Mark Polansky, commander; Joan Higginbotham, Robert Curbeam, British born Nicholas Patrick, Sunita Williams and the European Space Agency's Christer Fuglesang, all mission specialists. Curbeam, Fuglesang and Williams will conduct the space walks. Williams will not return with Discovery and instead join the ISS's current Expedition 14 and serve as a flight engineer aboard the station. Thomas Reiter, who arrived at the ISS onboard Discovery on mission STS-121 in July will return to Earth with the crew of STS-116 this month.
The launch of Discovery/STS-116 will potentially be the last from pad 39B as it is to be used for the development of NASA’s proposed Ares I crew launch vehicle. Shuttles will in future be launched from pad 39A. However because of NASA’s ongoing policy of launching a rescue shuttle if an Orbiter discovered it was damaged after its ascent pad 39B is required for a second Shuttle to be readied for flight for the Hubble Space Telescope servicing mission before pad 39A will be available.
Source: FlightGlobal.com
